Grinding apparatus



Oct. 10, 1933. M. MUSGRAVE GRINDING APPARATUS 2 Sheets-Sheet 1 flua rav'e Filed Say. 26, 1931 Oct. 10, 1933. M. MUSGRAVE 1,930,017

GRINDING APPARATU 5 Filed Sept. 26, 1931 2 Sheets-Sheet 2 zg/i 'Illlllllllllllld Patented Oct. 10, 1933 UNITED STATES GRINDING Mark Musgrave,

APPARATUS Springfield, Ohio Application September 26-, 1931 Serial No. 565,339

6 Claims.

This invention relates to grinding apparatus, and it is primarily an object of the invention to provide an apparatus of this kind especially designed and adapted for use in connection with automobile brake drums.

It is also an object of the invention to provide a device of this kind which is of a portable type and which is of a character to permit the same to be readily manipulated as required and which 0perates to eifectively grind or hone the braking surface of a brake drum or more particularly the inner face or surface of the flange of such drum.

The invention consists in the details of construction and in the combination and arrangement of the several parts of my improved grinding apparatus whereby certain important advan tages are attained and the device rendered simpler, less expensive and otherwise more convenient and advantageous for use, as will be 2 hereinafter more fully set forth.

The novel features of my invention will hereinafter be definitely claimed.

In order that my invention may be the better understood, I will now proceed to describe the 25831118 with reference to the accompanying drawings, wherein:-

Figure 1 is a view in top plan of an apparatus constructed in accordance with an embodiment of my invention with a portion broken away;

Figure 2 is a View partly in top plan and partly in section illustrating in detail the arms radiating from an end portion of the central spindle,

of the apparatus;

Figure 3 is a view in top plan of the adjusting sleeve herein employed unapplied;

Figure 4 is a fragmentary view in side elevation of the upper portion of the adjusting member;

Figure 5 is an elevational view of the second 49 adjustmentmember unapplied;

Figure 6 is a vertical sectional View taken sub stantially on the line 6-6 of Figure 1;

Figure 7 is a detailed sectional view taken substantially on the line 7-4 of Figure 1.

As disclosed in the accompanying drawings, 1 denotes an elongated central spindle of desired dimensions and cylindrical in cross section. This spindle is also disclosed in the accompanying drawings as tubular for lightening the weight thereof. Surrounding an end portion of the spindle 1 and fixedly secured thereto in any desired manner is an annular hub member 2 from which radiates a plurality of equidistantly spaced arms 3 which, as particularly illustrated in Figures 1 and 2 of the drawings, are four in number.

The outer end portion of each of the arms 3 is received within an end portion of a kerf 4 of a bifurcated swinging arm 5, said outer end portion of the arm 8 and the arm 5 being pivotally con- 50 nected by a pintle 6. The pintle 6 projects a desired distance above the pivoted end portion of the arm 5 and to said extended portion is fixed a double pulley 7.

This pulley 7 is in driving connection through a belt 8 with a pulley 9 fixed to the upper end portion of a shaft 10 rotatably disposed. through a bearing sleeve 11 carried by the outer portion of the arm 5. This shaft 10 below the bearing sleeve 11 carries a head 12 which is surrounded by a lamination 14 of sand paper or other suitable abrasive material.

Each of the arms 5 at a desired point intermediate its ends has pivotally connected thereto, as at 15, an end portion of a rigid link 16 which in turn is pivotally connected, as at 17, to an outstanding annular fiange 18 carried by an adjustment member 19. This member 19 snugly surrounds the central spindle l and, as particularly illustrated in Figure 6, rests from above upon the hub 2. This adjustment. member 19, as herein disclosed, constitutes a relatively long sleeve and at a desired point spaced from the flange 18 said member or sleeve 19 is provided with an outwardly and radially disposed operating arm 20. This arm 20 is fixed with respect to the sleeve or adjustment member. 19.

Each of the pulleys '7 is in driven engagement through a belt 21 with a double pulley 22 carried by the drive shaft 23 of a motor M. The motor M is of any desired electrical type and is secured to and supported directly by the central spindle 1. As the motor M-is of any preferred type a detailed description and illustration of the construction thereof is believed unnecessary. It is also believed to be obvious that the motor may be coupled in any desired or preferred manner with a desired source of'electrical energy.

In practice, it is preferred to use two motors M directly opposed for the purpose of balance and to have the drive shaft 23 of each of the motors M in electrical connection with two of the pulleys '7 at the same general side of the central spindle 1 as the motor.

Upon turning the adjusting member 19, which may be readily done through the medium of the arm 20 in the required direction, the various shafts 10 will be adjusted toward or from the central spindle 1 and it is believed to be clearly obvious from the foregoing description and accompanying drawings that such adjustment will in no way affect the operating means for each of said shafts.

Immediately adjacent to the adjusting member 19 the central spindle 1 is surrounded by a split band 24, the extremities of which having associated therewith a conventional clamping screw 25. This band 24 has extending therefrom a handle member 26 which normally lies closely adjacent to the operating arm or handle 20. In effecting a desired adjustment of the shafts 10 -of the flange of a brake drum comprising a suptoward or from the central spindle 1 an initial general adjustment in the desired direction is obtained by an operator moving in unison both of the arms or operating handles 20 and 26 whereupon the band 24 is tightly clamped to the central spindle 1. The outer portion of the handle 26 has threaded therethrough a screw 27 for engagement with the adjacent end portion of the arm or handle member 20 whereby when desired a fine or micrometer adjustment of the shafts 10 may be effected. The end portion of the central spindle 1 remote from the hub 2 has disposed transversely therethrough an elongated bar 28 providing means whereby the apparatus in its entirety may be readily lifted as desired and particularly providing means whereby the operatormay readily adjust the apparatus when in use for grinding or honing the inner braking surfaces or faces of brake drums.

The outer end portions of the arms 5 carry elongated arms 29 each of which being longitudinally adjustable in a direction lengthwise of the central spindle 1 and held in its desired adjustment by a binding member 30. The end portion of each of the arms 29 adjacent to a head 12 carries a roller 31. As illustrated in Figure 1, with the use of my improved apparatus the arms 29v are adjusted to have the rollers 31 extend slightly beyond the outer or free ends of the heads 12 so that the apparatus when in working position with respect to a brake drum D, as illustrated by broken lines in Figure 6, will be supported entirely by said arms 29 with the heads 12 of the various shafts 10 disposed substantially entirely across the inner or working face or surface of the flange of the drum D.

'After the operator places the apparatus within a drum, which is lying upon the ground or otherwise held in horizontal position, the adjusting member or sleeve 19 is operated to bring the abrasive surfaces 14 of the heads 12 into contact with the inner face or surface of the flange of the drum whereupon the motors M are caused to operate. As the shafts 10 rotate an effective grinding or honing of the inner or working surface or face of the brake drum will be effected and during the working operation the operator may readily rotate the apparatus as desired upon proper manipulation of the bar 28.

From the foregoing description it is thought to be obvious that a grinding apparatus constructed in accordance with my invention is particularly well adapted for use by reason of the convenience and facility with which it may be assembled and operated, and. it will also be obvious thatmy invention is susceptible of some change and modification without departing from the principles and spirit thereof and for this reason I do not wish to be understood aslimiting -myself to the precise arrangement and formation of the several parts herein shown in carrying out my invention in practice except as hereinafter claimed.

I claim:

1. An apparatus for honing the inner surface port member, means carried by the supporting member for riding contact upon the drum inwardly of its flange, arms radiating from the supporting member, arms pivotally connected to the first named arms, rotatable abrasive units abrasive units, and means for holding said sec- 0nd named arms against swinging movement.

2. An apparatus for honing the inner surface of the flange of a brake drum comprising a support member, means carried by the supporting member for riding contact upon the drum inwardly of its flange, arms radiating from the supporting member, arms pivotally connected to the first named arms, rotatable abrasive units carried by the second named arms and adapted for working engagement with the inner surface of the brake flange, means for rotating said abrasive units, and means for holding said second named arms against swinging movement, said last named means also operating to adjust the second arms toward or from the central member.

3. An apparatus for honing the inner surface of the flange of a brake drum comprising a support member, means carried by the supporting member for riding contact upon the drum inwardly of its flange, arms radiating from the supporting member, arms pivotally connected to the first named arms, rotatable abrasive units carried by the second named armsand adapted for working engagement with the inner surface of the brake flange, means for rotating said abrasive units, means for holding said second named arms against swinging movement, and support ing means for the apparatus carried by certain of the arms.

4. An apparatus for honing the inner surface of the flange of a brake drum comprising a central member, arms radiating therefrom, arms pivotally connected to the'first named arms, rotatable abrasive units carried by the second named arms and adapted for working engagement with the inner surface of the brake flange, means for rotating said abrasive units, means for holding said second named arms against swinging movement, and supporting means for the apparatus carried by the second named arms.

5. An apparatus for honing the inner surface of the flange of a brake drum comprising a support member, means carried by the supporting member for riding contact upon the drum inwardly of its flange, arms radiating from the supporting member, arms pivotally connected to the first named arms, rotatable abrasive units carried by the second named arms and adapted for working engagement with the inner sur face of the brake flange, means for rotating said abrasive units, an adjusting member rotatably carried by the central member, rigid members pivotally connected to the second named arms and to the adjusting member, and means for rotating the abrasive units, and means for holding said second named arms against swinging movement. a a

6. An apparatus for honing the inner surface of the flange of a brake drum comprising a central-member, arms radiating therefrom, arms pivotally connected to the first named arms, ro-

tatable abrasive units carried by the second named arms and adapted for working engagement with the inner surface of the brake flange, an adjusting member rotatably carried by the central member, rigid members pivotally connected to the second named arms and to the adjusting member, a handle freely mounted on the central member, means for fixing said handie to the central member, and means carried by said handle member and coacting with the adjusting member to effect a micrometer adjustment of the adjusting member.

MARK MUSGRAVE. 

